This meeting will focus on the control of signal transduction and cell cycle control by phosphorylation and posttranslational modifications, featuring pathways which are well studied and new mechanisms which are emerging. This is a large and rapidly moving field with direct applications towards clinical strategies for treatment of human disease. Molecular regulators of signal transduction pathways are proven therapeutic targets for clinical diseases, including cancer, diabetes, inflammation, arthritis, immunosuppression, hematopoietic defects, and heart disease. The first aim is to report new concepts and discoveries on mechanisms for cellular regulation by signaling molecules, as well as creative approaches towards the design and development of highly specific inhibitors for these targets. Our goal is to provide investigators and students with a broad yet comprehensive understanding of new discoveries in this field using biochemical, structural and genetic strategies. The second aim is to promote novel experimental approaches for participants to use in their research. Plenary talks will highlight innovative strategies towards problems in signal transduction, including monitoring global cellular responses by genomics, proteomics and database mining, new strategies for protein engineering, and fluorescence based assays for monitoring signal proteomics and bioinformatics to research problems. The third aim is to facilitate multidisciplinary thinking among participants. Our meeting will be held jointly with a Keystone Symposium on "Wnt and Beta- catenin Signaling in Development and Disease", which discuses mechanisms be which the Wnt signaling pathway is regulated in development and disease, ranging from basic research to clinical applications. Participants can choose between concurrent talks in each program, and two evening sessions will be held jointly. The two fields represented by these meetings overlap somewhat, but not so much that leading scientists in one field are necessarily recognizable by scientists in the other. Our goal is to provide participants with a venue to learn perspectives and the forefront of each discipline, as well as opportunities to crossfertilize and establish new contacts and collaborations.